Safety and economics concerns have accentuated an interest in energy input and consumption in the foods industry. This review article focuses on reported temperatures and temperature histories in food preparation and processing. To assist in interpreting reported data, a basic understanding of heat transfer parameters used is given. The relationships between temperature and time histories and quality effects of physical and chemical changes in foods, the production of new compounds with possible health effects, and microbiological safety are summarized. Several areas of needed research are identified.